T: allow using WithExperimentalFeatures in RsWithToolchainTestBase tests

Author: Undin

src/test/kotlin/org/rust/cargo/RsWithToolchainTestBase.kt

@@ -5,6 +5,7 @@
 
 package org.rust.cargo
 
+import com.intellij.findAnnotationInstance
 import com.intellij.openapi.Disposable
 import com.intellij.openapi.util.Disposer
 import com.intellij.openapi.util.RecursionManager
@@ -84,6 +85,7 @@ abstract class RsWithToolchainTestBase : CodeInsightFixtureTestCase<ModuleFixtur
         if (disableMissedCacheAssertions) {
             RecursionManager.disableMissedCacheAssertions(testRootDisposable)
         }
+        setupExperimentalFeatures()
         setupResolveEngine(project, testRootDisposable)
         findAnnotationInstance<ExpandMacros>()?.let { ann ->
             Disposer.register(
@@ -98,6 +100,12 @@ abstract class RsWithToolchainTestBase : CodeInsightFixtureTestCase<ModuleFixtur
         setExperimentalFeatureEnabled(RsExperiments.FETCH_ACTUAL_STDLIB_METADATA, fetchActualStdlibMetadata, testRootDisposable)
     }
 
+    private fun setupExperimentalFeatures() {
+        for (feature in findAnnotationInstance<WithExperimentalFeatures>()?.features.orEmpty()) {
+            setExperimentalFeatureEnabled(feature, true, testRootDisposable)
+        }
+    }
+
     override fun tearDown() {
         Disposer.dispose(earlyTestRootDisposable)
         rustupFixture.tearDown()
@@ -114,10 +122,6 @@ abstract class RsWithToolchainTestBase : CodeInsightFixtureTestCase<ModuleFixtur
     protected fun buildProject(builder: FileTreeBuilder.() -> Unit): TestProject =
         fileTree { builder() }.create()
 
-    /** Tries to find the specified annotation on the current test method and then on the current class */
-    private inline fun <reified T : Annotation> findAnnotationInstance(): T? =
-        javaClass.getMethod(name).getAnnotation(T::class.java) ?: javaClass.getAnnotation(T::class.java)
-
     /**
      * Tries to launches [action]. If it returns `false`, invokes [UIUtil.dispatchAllInvocationEvents] and tries again
      *